Buggy code:
public class JMXExtension implements Extension { public static final String SUBSYSTEM_NAME = "jmx" ; private static final String RESOURCE_NAME = ( JMXExtension . class . getPackage ( ) . getName ( ) ) + ".LocalDescriptions" ; static ResourceDescriptionResolver getResourceDescriptionResolver ( final String keyPrefix ) { } static final JMXExtension . JMXSubsystemParser_1_2 parserCurrent = new JMXExtension . JMXSubsystemParser_1_2 ( ) ; static final JMXExtension . JMXSubsystemParser_1_1 parser11 = new JMXExtension . JMXSubsystemParser_1_1 ( ) ; static final JMXExtension . JMXSubsystemParser_1_0 parser10 = new JMXExtension . JMXSubsystemParser_1_0 ( ) ; static final JMXExtension . JMXSubsystemWriter writer = new JMXExtension . JMXSubsystemWriter ( ) ; private static final int MANAGEMENT_API_MAJOR_VERSION = 1 ; private static final int MANAGEMENT_API_MINOR_VERSION = 1 ; private static final int MANAGEMENT_API_MICRO_VERSION = 0 ; @ Override public void initialize ( ExtensionContext context ) { final SubsystemRegistration registration = context . registerSubsystem ( JMXExtension . SUBSYSTEM_NAME , JMXExtension . MANAGEMENT_API_MAJOR_VERSION , JMXExtension . MANAGEMENT_API_MINOR_VERSION , JMXExtension . MANAGEMENT_API_MICRO_VERSION ) ; final boolean registerRuntimeOnly = context . isRuntimeOnlyRegistrationValid ( ) ; final ManagementResourceRegistration subsystem = registration . registerSubsystemModel ( new JMXSubsystemRootResource ( ) ) ; <START_BUG> subsystem . registerOperationHandler ( DESCRIBE , INSTANCE , INSTANCE , false , PRIVATE ) ; <END_BUG> subsystem . registerSubModel ( ExposeModelResourceResolved . INSTANCE ) ; subsystem . registerSubModel ( ExposeModelResourceExpression . INSTANCE ) ; subsystem . registerSubModel ( RemotingConnectorResource . INSTANCE ) ; registration . registerXMLElementWriter ( JMXExtension . writer ) ; registerTransformers1_0_0 ( registration ) ; } @ Override public void initializeParsers ( ExtensionParsingContext context ) { } private static ModelNode createAddOperation ( ) { } private static ModelNode createOperation ( String name , String ... addressElements ) { } private void registerTransformers1_0_0 ( SubsystemRegistration registration ) { } private static class JMXSubsystemParser_1_0 implements XMLStreamConstants , XMLElementReader < List < ModelNode > > { @ Override public void readElement ( XMLExtendedStreamReader reader , List < ModelNode > list ) throws XMLStreamException { } void parseConnector ( XMLExtendedStreamReader reader ) throws XMLStreamException { } } private static class JMXSubsystemParser_1_1 implements XMLStreamConstants , XMLElementReader < List < ModelNode > > { @ Override public void readElement ( XMLExtendedStreamReader reader , List < ModelNode > list ) throws XMLStreamException { } protected ModelNode parseRemoteConnector ( final XMLExtendedStreamReader reader ) throws XMLStreamException { } private boolean parseShowModelElement ( XMLExtendedStreamReader reader ) throws XMLStreamException { } } private static class JMXSubsystemParser_1_2 extends JMXExtension . JMXSubsystemParser_1_1 { @ Override public void readElement ( XMLExtendedStreamReader reader , List < ModelNode > list ) throws XMLStreamException { } private ModelNode parseShowModelElement ( XMLExtendedStreamReader reader , String showModelChild ) throws XMLStreamException { } } private static class JMXSubsystemWriter implements XMLStreamConstants , XMLElementWriter < SubsystemMarshallingContext > { @ Override public void writeContent ( XMLExtendedStreamWriter writer , SubsystemMarshallingContext context ) throws XMLStreamException { } } }

Fix:
subsystem . registerOperationHandler ( DEFINITION , INSTANCE ) ;